Customer needs to shutdown the cluster and would like to know how to do it properly, without any data loss or volume inconsistencies.
"Should I first stop the cluster and then stop the replication task?
Once this is done, Can I just shutdown both servers?"
In order to stop cluster gracefully, please STOP the cluster in:
[ DSS WebGUI > Setup > Failover ]
tab and just shutdown both nodes.
Also, there is a tool available called "dss-tools.exe", which can remotely stop the cluster in a graceful manner and start it again automatically.
This tool can be downloaded from github: